Presentation on theme: "Spatial scales of homing and the efficacy of hatchery supplementation of wild populations Northwest Fisheries Science Center National Marine Fisheries."— Presentation transcript:
Spatial scales of homing and the efficacy of hatchery supplementation of wild populations Northwest Fisheries Science Center National Marine Fisheries Service Seattle, Washington Project # 35012
Significance to Regional Programs Mainstem/Systemwide Artificial Production Program summary: Studies of hatchery effects on straying (homing and imprinting) are needed to manage straying rates of hatchery adults and assess the effects of straying on wild populations and stream productivity (BPA Gap Analysis: Needing immediate implementation for both BIOP and FWP) RPA 184 Evaluate Hatchery Reforms - employ hatchery practices that reduce unwanted straying of hatchery fish - assess frequency and magnitude of … interactions between wild and hatchery fish - test the efficacy of acclimation sites for imprinting and homing to target areas and the interactions and ecological overlap of hatchery fish with wild populations. RPA 182: Determine the reproductive success of hatchery fish - identify temporal and spatial distribution of [hatchery] spawners relative to wild fish. RPA 107 Identify causes of unaccounted losses of migrating adults.
Hatchery Supplementation of Wild Salmon: Yakima River Extensive tagging and monitoring Pre-supplementation data Minimal hatchery influence Multi-agency cooperation Accessible Ecological, chemical and geomorphological diversity
Cle Elum Hatchery Acclimation site (Easton) Acclimation site (Jack Creek) Acclimation site (Clark Flat) YKFP Spring chinook supplementation research program Wild broodstock collected at Roza Dam Reared at Cle Elum Hatchery 16 months until smolting Transfer to acclimation sites and volitional release All fish: site-specific CWTs, eye tags; 5-10% pit tag Returning hatchery adults spawn naturally/redd surveys
Objectives 1)Identify and compare the fine spatial and temporal patterns of homing and spawning of wild and YKFP supplementation salmon relative to the Cle Elum hatchery, acclimation sites, and historical and current spawning reaches. 2)Describe and compare the prespawning migratory behaviors (e.g. exploring, proving, holding) and spawning site selection of homing wild and YKFP supplementation fish from each of the acclimation sites using radiotelemetry. 3) Characterize the site-specific physiological changes that occur in the olfactory system during imprinting to different acclimation sites to assess imprinting success.
Objective 1. Spatial and temporal patterns of homing and spawning of wild and supplemented salmon H o : Carcass distribution is not dependent on site of acclimation and release -distributions relative to acclimation site -nearest-neighbor analysis for clustering -differences in temporal distribution (spawn timing) -migratory history H o : Carcass distribution is not different for wild and hatchery fish H 0 : Carcass distribution of wild fish does not differ from pre-supplementation H 0 : Patterns of redd distribution and clustering does not change over the spawning season or between years
Objective 1. Spatial and temporal patterns of homing and spawning of wild and supplemented salmon Methods Weekly comprehensive surveys of entire upper Yakima Basin Carcasses -GPS location (3 m accuracy); date -hatchery/wild -male/female; jack, precocious -length -tag location, recovery -egg retention; disease Redds -Yakama biologists survey and flag (color coded by date) all redds in upper Yakima - GPS mapping of all redds in the upper Yakima at end of spawning season
Objective 2. Describe and compare the pre-spawning migratory behaviors (e.g. exploring, proving, holding) using radiotelemetry H 0 : Prespawning movements of salmon released from different sites do not differ H 0 : Prespawning movements of wild/hatchery salmon do not differ H 0 : Prespawning movements of wild fish do not change after supplementation -Radiotelemetry: 25 fish/treatment -Fixed-site receivers -Standardized surveys with portable receiver -GPS mapping -Comparison to pre-supplementation radiotelemetry
Objective 3. Characterize physiological changes that occur in the olfactory system during imprinting H 0 : Olfactory sensitivity to specific odorants/water sources does not differ in fish reared and released from different sites -EOG analysis of Cle Elum hatchery and acclimation site smolts -Chemical analysis of hatchery/acclimation waters -Molecular analysis of olfactory rosettes